Method and apparatus for indicating preempted resource information

ABSTRACT

A method for receiving a signal in a user equipment (UE) from a base station (BS) in a wireless communication system is disclosed. The method comprises the steps of configuring a plurality of intervals of a specific time region for indicating whether to transmit the signal, through a higher layer; receiving an indicator for indicating whether to transmit the signal, for each of the plurality of intervals; and receiving a signal in each of the plurality of intervals in accordance with indication of the received indicator, wherein at least one of the plurality of intervals of the specific time region may have a first size, and the other intervals except the at least one interval may have a second size.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage filing under 35 U.S.C. 371 ofInternational Application No. PCT/KR2018/001380, filed on Feb. 1, 2018,which claims the benefit of U.S. Provisional Application No. 62/454,008,filed on Feb. 2, 2017, 62/469,454, filed on Mar. 9, 2017, 62/539,490,filed on Jul. 31, 2017, 62/555,627, filed on Sep. 7, 2017, 62/565,052,filed on Sep. 28, 2017, and 62/616,413, filed on Jan. 11, 2018, thecontents of which are all hereby incorporated by reference herein intheir entirety.

TECHNICAL FIELD

The present invention relates to a method for indicating pre-emptedresource information and an apparatus therefor, and more particularly,to an indicating method of an indicator for a pre-empted resource toefficiently indicate the pre-empted resource, a method for setting anindication period, and an apparatus therefor.

BACKGROUND ART

As more communication devices require greater communication capacity inaccordance with the trend, a next generation 5G system which is mobilebroadband communication more enhanced than the conventional LTE systemhas been required. In the next generation 5G system referred to asNewRAT, a communication scenario is categorized into Enhanced MobileBroadBand (eMBB)/Ultra-reliability and Low-Latency Communication(URLLC)/Massive Machine-Type Communications (mMTC).

In this case, eMBB is a next generation communication scenario havingproperties such as High Spectrum Efficiency, High User Experienced DataRate, and High Peak Data Rate, and URLLC is a next generationcommunication scenario (e.g., V2X, Emergency Service, Remote Control)having properties such as Ultra Reliable, Ultra Low Latency, and UltraHigh Availability, and mMTC is a communication scenario (e.g., IoT)having properties such as Low Cost, Low Energy, Short Packet, andMassive Connectivity.

Technical Problem

An object of the present invention is to provide a method for indicatingpre-empted resource information in a wireless communication system andan apparatus therefor.

Technical tasks obtainable from the present invention are non-limited bythe above-mentioned technical task. And, other unmentioned technicaltasks can be clearly understood from the following description by thosehaving ordinary skill in the technical field to which the presentinvention pertains.

Technical Solution

According to the embodiment of the present invention, a method forreceiving a signal in a user equipment (UE) from a base station (BS) ina wireless communication system comprises the steps of configuring aplurality of durations, sometimes also referred to as intervals, of aspecific time region for indicating whether a signal is transmitted,through a higher layer; receiving an indicator for indicating whetherthe signal is transmitted, for each of the plurality of intervals; andreceiving the signal in each of the plurality of intervals in accordancewith indication of the received indicator, wherein at least one of theplurality of intervals of the specific time region may have a firstsize, and the other intervals except the at least one interval may havea second size.

In this case, the first size and the second size may be values differentfrom each other.

Also, the first size and the second size may be determined based on avalue obtained by dividing a size of the specific time region by anumber of the plurality of intervals.

Also, the first size may be ┌T/M┐, the second size may be └T/M┘, whereinT may be a size of the specific time region and M may be the number ofthe plurality of intervals.

Also, a number of at least one interval having the first size may bedetermined based on a value obtained by dividing the size of thespecific time region by a number of the plurality of intervals.

Also, the number of at least one interval having the first size may beT−M└T/M┘, and the number of the other intervals having the second sizemay be

${M - ( {T - {M\lfloor \frac{T}{M} \rfloor}} )},$wherein T may be a size of the specific time region and M may be thenumber of the plurality of intervals.

Also, the plurality of intervals may be configured for the specific timeregion and a specific frequency region.

A monitoring period of the indicator indicating whether the signal istransmitted may be associated with the size of the specific time region.

Also, the plurality of intervals may be configured if a parameter as towhether a region to which the signal is not transmitted exists isreceived from the higher layer.

Also, the specific time region may include a time region for receiving adownlink.

Also, the monitoring period of the indicator indicating whether thesignal is transmitted may be the same as a time region where an intervalfor uplink transmission to the specific time region is added.

Also, the indicator indicating whether the signal is transmitted mayindicate whether the signal is transmitted for a resource from aprevious symbol of a first symbol of a slot at which the indicator ismonitored to the time region where the interval for uplink transmissionis added.

Also, the indicator indicating whether the signal is transmitted mayinclude a plurality of bits, of each of the plurality of intervals, forindicating whether the signal is transmitted.

A UE for receiving a signal from a base station (BS) in a wirelesscommunication system according to the present invention comprises an RFmodule for transmitting and receiving a signal to and from the BS; and aprocessor connected with the RF module, configuring a plurality ofintervals of a specific time region for indicating whether the signal istransmitted, through a higher layer, receiving an indicator forindicating whether the signal is transmitted, for each of the pluralityof intervals, and receiving a signal in each of the plurality ofintervals in accordance with indication of the received indicator,wherein at least one of the plurality of intervals of the specific timeregion has a first size, and the other intervals except the at least oneinterval have a second size.

Advantageous Effects

According to the present invention, uplink resources between physicalchannels in which required transmission methods are different like eMBBand URLLC may be shared efficiently.

Also, information on a pre-empted resource region is segmented andtransmitted, whereby the information on a pre-empted resource region mayefficiently be indicated to a UE.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram for structures of control and user planes of radiointerface protocol between a 3GPP radio access network standard-baseduser equipment and E-UTRAN;

FIG. 2 is a diagram for explaining physical channels used for 3GPPsystem and a general signal transmission method using the physicalchannels;

FIG. 3 is a diagram for a structure of a radio frame in LTE system;

FIG. 4 illustrates a structure of a downlink radio frame in the LTEsystem;

FIG. 5 illustrates a structure of an uplink subframe in the LTE system;

FIG. 6 illustrates examples of a connection scheme between TXRUs andantenna elements.

FIG. 7 illustrates an example of a self-contained subframe structure;

FIG. 8 illustrates an embodiment of a bit field size indicating apre-empted resource;

FIG. 9 illustrates an embodiment according to a method for indicating anindicator for a pre-empted resource;

FIGS. 10 and 11 illustrate a time domain and an indication periodindicated by an indicator for a pre-empted resource; and

FIG. 12 is a block diagram of a communication apparatus according to anembodiment of the present disclosure.

BEST MODE FOR CARRYING OUT THE INVENTION

The configuration, operation, and other features of the presentdisclosure will readily be understood with embodiments of the presentdisclosure described with reference to the attached drawings.Embodiments of the present disclosure as set forth herein are examplesin which the technical features of the present disclosure are applied toa 3rd Generation Partnership Project (3GPP) system.

While embodiments of the present disclosure are described in the contextof Long Term Evolution (LTE) and LTE-Advanced (LTE-A) systems, they arepurely exemplary. Therefore, the embodiments of the present disclosureare applicable to any other communication system as long as the abovedefinitions are valid for the communication system.

The term ‘Base Station (BS)’ may be used to cover the meanings of termsincluding Remote Radio Head (RRH), evolved Node B (eNB or eNode B),Reception Point (RP), relay, etc.

FIG. 1 illustrates control-plane and user-plane protocol stacks in aradio interface protocol architecture conforming to a 3GPP wirelessaccess network standard between a User Equipment (UE) and an EvolvedUMTS Terrestrial Radio Access Network (E-UTRAN). The control plane is apath in which the UE and the E-UTRAN transmit control messages to managecalls, and the user plane is a path in which data generated from anapplication layer, for example, voice data or Internet packet data istransmitted.

A PHYsical (PHY) layer at Layer 1 (L1) provides information transferservice to its higher layer, a Medium Access Control (MAC) layer. ThePHY layer is connected to the MAC layer via transport channels. Thetransport channels deliver data between the MAC layer and the PHY layer.Data is transmitted on physical channels between the PHY layers of atransmitter and a receiver. The physical channels use time and frequencyas radio resources. Specifically, the physical channels are modulated inOrthogonal Frequency Division Multiple Access (OFDMA) for Downlink (DL)and in Single Carrier Frequency Division Multiple Access (SC-FDMA) forUplink (UL).

The MAC layer at Layer 2 (L2) provides service to its higher layer, aRadio Link Control (RLC) layer via logical channels. The RLC layer at L2supports reliable data transmission. RLC functionality may beimplemented in a function block of the MAC layer. A Packet DataConvergence Protocol (PDCP) layer at L2 performs header compression toreduce the amount of unnecessary control information and thusefficiently transmit Internet Protocol (IP) packets such as IP version 4(IPv4) or IP version 6 (IPv6) packets via an air interface having anarrow bandwidth.

A Radio Resource Control (RRC) layer at the lowest part of Layer 3 (orL3) is defined only on the control plane. The RRC layer controls logicalchannels, transport channels, and physical channels in relation toconfiguration, reconfiguration, and release of radio bearers. A radiobearer refers to a service provided at L2, for data transmission betweenthe UE and the E-UTRAN. For this purpose, the RRC layers of the UE andthe E-UTRAN exchange RRC messages with each other. If an RRC connectionis established between the UE and the E-UTRAN, the UE is in RRCConnected mode and otherwise, the UE is in RRC Idle mode. A Non-AccessStratum (NAS) layer above the RRC layer performs functions includingsession management and mobility management.

DL transport channels used to deliver data from the E-UTRAN to UEsinclude a Broadcast Channel (BCH) carrying system information, a PagingChannel (PCH) carrying a paging message, and a Shared Channel (SCH)carrying user traffic or a control message. DL multicast traffic orcontrol messages or DL broadcast traffic or control messages may betransmitted on a DL SCH or a separately defined DL Multicast Channel(MCH). UL transport channels used to deliver data from a UE to theE-UTRAN include a Random Access Channel (RACH) carrying an initialcontrol message and a UL SCH carrying user traffic or a control message.Logical channels that are defined above transport channels and mapped tothe transport channels include a Broadcast Control Channel (BCCH), aPaging Control Channel (PCCH), a Common Control Channel (CCCH), aMulticast Control Channel (MCCH), a Multicast Traffic Channel (MTCH),etc.

FIG. 2 illustrates physical channels and a general method fortransmitting signals on the physical channels in the 3GPP system.

Referring to FIG. 2, when a UE is powered on or enters a new cell, theUE performs initial cell search (S201). The initial cell search involvesacquisition of synchronization to an eNB. Specifically, the UEsynchronizes its timing to the eNB and acquires a cell Identifier (ID)and other information by receiving a Primary Synchronization Channel(P-SCH) and a Secondary Synchronization Channel (S-SCH) from the eNB.Then the UE may acquire information broadcast in the cell by receiving aPhysical Broadcast Channel (PBCH) from the eNB. During the initial cellsearch, the UE may monitor a DL channel state by receiving a DownLinkReference Signal (DL RS).

After the initial cell search, the UE may acquire detailed systeminformation by receiving a Physical Downlink Control Channel (PDCCH) andreceiving a Physical Downlink Shared Channel (PDSCH) based oninformation included in the PDCCH (S202).

If the UE initially accesses the eNB or has no radio resources forsignal transmission to the eNB, the UE may perform a random accessprocedure with the eNB (S203 to S206). In the random access procedure,the UE may transmit a predetermined sequence as a preamble on a PhysicalRandom Access Channel (PRACH) (S203 and S205) and may receive a responsemessage to the preamble on a PDCCH and a PDSCH associated with the PDCCH(S204 and S206). In the case of a contention-based RACH, the UE mayadditionally perform a contention resolution procedure.

After the above procedure, the UE may receive a PDCCH and/or a PDSCHfrom the eNB (S207) and transmit a Physical Uplink Shared Channel(PUSCH) and/or a Physical Uplink Control Channel (PUCCH) to the eNB(S208), which is a general DL and UL signal transmission procedure.Particularly, the UE receives Downlink Control Information (DCI) on aPDCCH. Herein, the DCI includes control information such as resourceallocation information for the UE. Different DCI formats are definedaccording to different usages of DCI.

Control information that the UE transmits to the eNB on the UL orreceives from the eNB on the DL includes a DL/UL ACKnowledgment/NegativeACKnowledgment (ACK/NACK) signal, a Channel Quality Indicator (CQI), aPrecoding Matrix Index (PMI), a Rank Indicator (RI), etc. In the 3GPPLTE system, the UE may transmit control information such as a CQI, aPMI, an RI, etc. on a PUSCH and/or a PUCCH.

FIG. 3 illustrates a structure of a radio frame used in the LTE system.

Referring to FIG. 3, a radio frame is 10 ms (327200xTs) long and dividedinto 10 equal-sized subframes. Each subframe is 1 ms long and furtherdivided into two slots. Each time slot is 0.5 ms (15360×Ts) long.Herein, Ts represents a sampling time and Ts=1/(15 kHz×2048)=3.2552×10-8(about 33 ns). A slot includes a plurality of Orthogonal FrequencyDivision Multiplexing (OFDM) symbols or SC-FDMA symbols in the timedomain by a plurality of Resource Blocks (RBs) in the frequency domain.In the LTE system, one RB includes 12 subcarriers by 7 (or 6) OFDMsymbols. A unit time during which data is transmitted is defined as aTransmission Time Interval (TTI). The TTI may be defined in units of oneor more subframes. The above-described radio frame structure is purelyexemplary and thus the number of subframes in a radio frame, the numberof slots in a subframe, or the number of OFDM symbols in a slot mayvary.

FIG. 4 illustrates exemplary control channels included in a controlregion of a subframe in a DL radio frame.

Referring to FIG. 4, a subframe includes 14 OFDM symbols. The first oneto three OFDM symbols of a subframe are used for a control region andthe other 13 to 11 OFDM symbols are used for a data region according toa subframe configuration. In FIG. 4, reference characters R1 to R4denote RSs or pilot signals for antenna 0 to antenna 3. RSs areallocated in a predetermined pattern in a subframe irrespective of thecontrol region and the data region. A control channel is allocated tonon-RS resources in the control region and a traffic channel is alsoallocated to non-RS resources in the data region. Control channelsallocated to the control region include a Physical Control FormatIndicator Channel (PCFICH), a Physical Hybrid-ARQ Indicator Channel(PHICH), a Physical Downlink Control Channel (PDCCH), etc.

The PCFICH is a physical control format indicator channel carryinginformation about the number of OFDM symbols used for PDCCHs in eachsubframe. The PCFICH is located in the first OFDM symbol of a subframeand configured with priority over the PHICH and the PDCCH. The PCFICHincludes 4 Resource Element Groups (REGs), each REG being distributed tothe control region based on a cell Identity (ID). One REG includes 4Resource Elements (REs). An RE is a minimum physical resource defined byone subcarrier by one OFDM symbol. The PCFICH is set to 1 to 3 or 2 to 4according to a bandwidth. The PCFICH is modulated in Quadrature PhaseShift Keying (QPSK).

The PHICH is a physical Hybrid-Automatic Repeat and request (HARQ)indicator channel carrying an HARQ ACK/NACK for a UL transmission. Thatis, the PHICH is a channel that delivers DL ACK/NACK information for ULHARQ. The PHICH includes one REG and is scrambled cell-specifically. AnACK/NACK is indicated in one bit and modulated in Binary Phase ShiftKeying (BPSK). The modulated ACK/NACK is spread with a Spreading Factor(SF) of 2 or 4. A plurality of PHICHs mapped to the same resources forma PHICH group. The number of PHICHs multiplexed into a PHICH group isdetermined according to the number of spreading codes. A PHICH (group)is repeated three times to obtain a diversity gain in the frequencydomain and/or the time domain.

The PDCCH is a physical DL control channel allocated to the first n OFDMsymbols of a subframe. Herein, n is 1 or a larger integer indicated bythe PCFICH. The PDCCH occupies one or more CCEs. The PDCCH carriesresource allocation information about transport channels, PCH andDL-SCH, a UL scheduling grant, and HARQ information to each UE or UEgroup. The PCH and the DL-SCH are transmitted on a PDSCH. Therefore, aneNB and a UE transmit and receive data usually on the PDSCH, except forspecific control information or specific service data.

Information indicating one or more UEs to receive PDSCH data andinformation indicating how the UEs are supposed to receive and decodethe PDSCH data are delivered on a PDCCH. For example, on the assumptionthat the Cyclic Redundancy Check (CRC) of a specific PDCCH is masked byRadio Network Temporary Identity (RNTI) “A” and information about datatransmitted in radio resources (e.g. at a frequency position) “B” basedon transport format information (e.g. a transport block size, amodulation scheme, coding information, etc.) “C” is transmitted in aspecific subframe, a UE within a cell monitors, that is, blind-decodes aPDCCH using its RNTI information in a search space. If one or more UEshave RNTI “A”, these UEs receive the PDCCH and receive a PDSCH indicatedby “B” and “C” based on information of the received PDCCH.

FIG. 5 illustrates a structure of a UL subframe in the LTE system.

Referring to FIG. 5, a UL subframe may be divided into a control regionand a data region. A Physical Uplink Control Channel (PUCCH) includingUplink Control Information (UCI) is allocated to the control region anda Physical uplink Shared Channel (PUSCH) including user data isallocated to the data region. The middle of the subframe is allocated tothe PUSCH, while both sides of the data region in the frequency domainare allocated to the PUCCH. Control information transmitted on the PUCCHmay include an HARQ ACK/NACK, a CQI representing a downlink channelstate, an RI for Multiple Input Multiple Output (MIMO), a SchedulingRequest (SR) requesting UL resource allocation. A PUCCH for one UEoccupies one RB in each slot of a subframe. That is, the two RBsallocated to the PUCCH are frequency-hopped over the slot boundary ofthe subframe. Particularly, PUCCHs with m=0, m=1, and m=2 are allocatedto a subframe in FIG. 6.

Hereinafter, channel state information (CSI) reporting will be describedbelow. In the current LTE standard, there are two MIMO transmissionschemes, open-loop MIMO operating without channel information andclosed-loop MIMO operating with channel information. Particularly in theclosed-loop MIMO, each of an eNB and a UE may perform beamforming basedon CSI to obtain the multiplexing gain of MIMO antennas. To acquire CSIfrom the UE, the eNB may command the UE to feed back CSI on a downlinksignal by allocating a PUCCH (Physical Uplink Control CHannel) or aPUSCH (Physical Uplink Shared CHannel) to the UE.

The CSI is largely classified into three information types, RI (RankIndicator), PMI (Precoding Matrix), and CQI (Channel QualityIndication). First of all, the RI indicates rank information of achannel as described above, and means the number of streams that may bereceived by a UE through the same time-frequency resources. Also, sincethe RI is determined by long-term fading of a channel, the RI may be fedback to an eNB in a longer period than a PMI value and a CQI value.

Second, the PMI is a value obtained by reflecting spatialcharacteristics of a channel, and indicates a precoding matrix index ofan eNB, which is preferred by the UE based on a metric such as signal tointerference and noise ratio (SINR). Finally, the CQI is a valueindicating channel strength, and generally means a reception SINR thatmay be obtained by the eNB when the PMI is used.

In the 3GPP LTE-A system, the eNB may configure a plurality of CSIprocesses for the UE, and may be reported CSI for each of the CSIprocesses. In this case, the CSI process includes CSI-RS resource forspecifying signal quality and CSI-IM (interference measurement)resource, that is, IMR (interference measurement resource) forinterference measurement.

Since a wavelength becomes short in the field of Millimeter Wave (mmW),a plurality of antenna elements may be installed in the same area. Inmore detail, a wavelength is 1 cm in a band of 30 GHz, and a total of64(8×8) antenna elements of a 2D array may be installed in a panel of 4by 4 cm at an interval of 0.5 lambda (wavelength). Therefore, a recenttrend in the field of mmW attempts to increase coverage or throughput byenhancing BF (beamforming) gain using a plurality of antenna elements.

In this case, if a transceiver unit (TXRU) is provided to control atransmission power and phase per antenna element, independentbeamforming may be performed for each frequency resource. However, aproblem occurs in that effectiveness is deteriorated in view of costwhen TXRU is provided for all of 100 antenna elements. Therefore, ascheme is considered, in which a plurality of antenna elements aremapped into one TXRU and a beam direction is controlled by an analogphase shifter. Since this analog beamforming scheme may make only onebeam direction in a full band, a problem occurs in that frequencyselective beamforming is not available.

As an intermediate type of digital BF and analog BF, a hybrid BF havingB TXRUs smaller than Q antenna elements may be considered. In this case,although there is a difference depending on a connection scheme of BTXRUs and Q antenna elements, the number of beam directions that enablesimultaneous transmission is limited to B or less.

FIG. 6 illustrates examples of a connection scheme between TXRUs andantenna elements.

(a) of FIG. 6 illustrates that TXRU is connected to a sub-array. In thiscase, the antenna elements are connected to only one TXRU. Unlike (a) ofFIG. 6, (b) of FIG. 6 illustrates that TXRU is connected to all antennaelements. In this case, the antenna elements are connected to all TXRUs.In FIG. 7, W indicates a phase vector multiplied by an analog phaseshifter. That is, a direction of analog beamforming is determined by W.In this case, mapping between CSI-RS antenna ports and TXRUs may be1-to-1 or 1-to-many.

As more communication devices require greater communication capacity,the need of mobile broadband communication more advanced than theconventional RAT (radio access technology) has been issued. Also,massive MTC (Machine Type Communications) technology that providesvarious services anywhere and at any time by connecting a plurality ofdevices and things is one of main issues which will be considered innext generation communication. Furthermore, a communication systemdesign considering service/UE susceptible to reliability and latency hasbeen discussed. Considering this status, the introduction of the nextgeneration RAT has been discussed, and the next generation RAT will bereferred to as NewRAT in the present invention.

A self-contained subframe structure shown in FIG. 7 is considered in thefifth generation NewRAT to minimize data transmission latency in a TDDsystem. FIG. 7 illustrates an example of a self-contained subframestructure.

In FIG. 7, oblique line areas indicate downlink control regions andblack colored areas indicate uplink control regions. Areas having nomark may be used for downlink data transmission or uplink datatransmission. In this structure, downlink transmission and uplinktransmission are performed in due order within one subframe, wherebydownlink data may be transmitted and uplink ACK/NACK may be receivedwithin the subframe. As a result, the time required for datare-transmission may be reduced when an error occurs in datatransmission, whereby latency of final data transfer may be minimized.

In this self-contained subframe structure, a time gap for switching froma transmission mode to a reception mode or vice versa is required forthe eNB and the UE. To this end, some OFDM symbols (OS) at the time whena downlink is switched to an uplink in the self-contained subframestructure are set to a guard period.

Examples of the self-contained subframe type that may be configured inthe system operating based on the NewRAT may consider four subframetypes as follows.

-   -   downlink control period+downlink data period+GP+uplink control        period    -   downlink control period+downlink data period    -   downlink control period+GP+uplink data period+uplink control        period    -   downlink control period+GP+uplink data period

In the fifth generation NewRAT system, various reference time units usedto transmit and receive physical channels may exist in accordance withan application field or a type of traffic. The reference time may be abasic unit for scheduling a specific physical channel, and a referencetime unit may be varied depending on the number of symbols constitutinga corresponding scheduling unit and/or a subcarrier spacing.

In the embodiment of the present invention, it is assumed that areference time unit is a slot and a mini-slot for convenience ofdescription. The slot may be a basic unit of scheduling used for generaldata traffic in the same manner as data transmitted from an enhancedMobile BroadBand (eMBB). The mini-slot has a time interval smaller thana slot in a time domain, and may be a basic unit of scheduling used intraffic or communication mode for a specific purpose in the same manneras Ultra Reliable and Low Latency Communication (URLLC), non-licensedband or millimeter wave. Also, in the embodiment, which will bedescribed later, the mini-slot may be represented by a specific symbolgroup including a single symbol.

However, the aforementioned description is only an embodiment forconvenience of description of the present invention, and it will beapparent that the aforementioned description can be extended from thespirits of the present invention even in the case that eMBB transmitsand receives physical channels based on the mini-slot or URLLC oranother communication scheme transmits and receives physical channelsbased on slot.

In slot based transmission (hereinafter, eMBB transmission),transmission may occur for a relatively long time as compared with arelatively mini-slot based transmission (hereinafter, URLLC). In case ofURLLC traffic, it is general that an urgent packet may occur suddenly,especially URLLC traffic may occur in the middle of eMBB transmission.

Meanwhile, since superposition in downlink transmission occurs in allbase station ends, a method for puncturing some resources of eMBB may beused to protect URLLC data. However, since transmission entities may bedifferent UEs in case of superposition in uplink transmission, uplinkchannel reception performance may be reduced remarkably due to collisionbetween eMBB data and URLLC data unless a specific action is taken.

To solve this problem, the present invention intends to suggest a methodefficiently multiplexing physical channels transmitted at theirrespective time units different from each other when transmission andreception are performed in a plurality of reference time units such assubframe, slot or mini-slot.

In the next generation system, time and/or frequency resources for URLLCuplink transmission may basically be configured through higher layersignaling. In detail, a resource set may be configured independentlydepending on whether an uplink transmission scheme is grant-based ULtransmission or grant-free UL transmission. If the resource set isconfigured independently as above and eMBB transmission and URLLCtransmission collide with each other, it may be useful that eMBBtransmission and URLLC transmission may be processed in their respectivemethods different from each other. Meanwhile, in this case, grant-freeUL transmission may mean that the UE selects a specific resource amongresources allocated previously or from a higher layer and performsuplink transmission for the selected specific resource withoutscheduling indication of the base station.

Meanwhile, although the embodiment of the present invention has beendescribed based on an uplink channel and signal, the embodiment of thepresent invention is not limited to the uplink channel and signal andmay be applied to a downlink channel and signal.

<Halting On-Going Transmission of eMBB>

If eMBB uplink transmission and URLLC transmission are subjected tosuperposition, detection performance of two channels may be reducedrapidly due to mutual interference. Particularly, in case of URLLC,substantial latency may be longer due to detection failure. As a methodfor solving this problem, transmission of eMBB uplink channel which ispreviously being transmitted may be halted only at the time when URLLCuplink channel is transmitted or transmission from the time when URLLCuplink channel is transmitted may be halted. To this end, the eMBB UEmay need to recognize the presence of the URLLC uplink channel in themiddle of transmission.

Therefore, the present invention intends to suggest an embodiment of amethod for recognizing the presence of URLLC uplink channel through eMBBUE and halting eMBB transmission, as follows.

Embodiment 1-1

It is considered that the eMBB UE detects uplink grant for URLCC, DCIfor control and/or a DMRS for uplink channel For the above scheme, thebase station may signal information for detecting URLLC signal,UE-specifically. In detail, the information for detecting URLLC signalmay be candidates of DCI and/or DMRS.

Meanwhile, instead of UE-specifically configuring DCI and/or DMRS forURLLC, the DCI and/or DMRS for URLLC may be configuredcell-specifically, beam-specifically or UE-group commonly.

However, if numerologies between eMBB and URLLC are different from eachother, it may not be suitable that DCI and/or DMRS for URLLC isconfigured cell-specifically, beam-specifically or UE-group commonly. Inthis case, the base station may transmit information on a halting signalin accordance with eMBB numerology. That is, the eMBB UE may detectinformation on a halting signal from the base station and, after acertain time, may halt eMBB transmission at only a corresponding time orafter the corresponding time. For example, URLLC performs grant baseduplink transmission, the eMBB UE may detect information on atransmission time of URLLC uplink signal from the base station and, andmay halt eMBB transmission at only a corresponding time or after thecorresponding time.

However, according to the aforementioned example, an operation may bedifficult if URLLC performs grant-free UL transmission. Therefore, aresource for grant-free UL transmission may be reserved. In other words,the resource for grant-free UL transmission of URLLC may not be used byeMBB uplink.

Embodiment 1-2

The eMBB UE may take an LBT (listen before talk) scheme for URLLCsignal. That is, the eMBB UE may measure whether the URLLC signal istransmitted from another UE by means of a method such as energydetection during eMBB uplink transmission, and may halt eMBB signaltransmission based on the measurement.

However, in the aforementioned case, if a distance between the two UEsis distant, that is, if a hidden-node problem occurs, the aforementionedoperation may not be performed normally.

Therefore, if eMBB signal transmission halting for taking the LBT schemeis not performed normally, that is, as the distance between the two UEsis distant at a certain distance or more, although eMBB uplinktransmission has been performed, if a problem such as interferencecaused by eMBB uplink transmission occurs, returning to the embodiment1, a signal for URLLC signal transmission may be received from the basestation. At this time, if the base station discovers interference causedby URLLC uplink transmission and uplink transmission of the eMBB UE inthe middle of performing the corresponding operation by assuming thatuplink transmission is performed based on LBT, the base station mayindicate, to the UE, to halt eMBB uplink transmission based on the LBTscheme and perform the operation according to the embodiment 1.

Meanwhile, a control channel monitoring behaviour performed while theURLLC signal of the UE multi-slot scheduled or multi-mini-slot scheduledis being transmitted and received may be as follows.

(1) If control channel monitoring is configured to be performed perslot, control channel monitoring is performed per slot.Suspension/drop/continue indication for multi-slot scheduling which isongoing may be designated through a control channel This indicationcontent or type may be notified using RNTI, CRC, scrambling, DMRSsequence or scrambling differently. Otherwise, transmission search spacecandidates or resources may be configured differently to identifyoperations such as suspension/drop/continue. That is, if suspension ordrop of multi-slot scheduling is indicated, control channel monitoringmay be suspended or dropped after control channel monitoring indicatedby suspension or drop within a corresponding interval, and if indicationis continuously designated, control channel monitoring is maintained perslot, whereby multi-slot scheduling may be indicated continuously.

(2) In case of multi-slot scheduling, the control channel monitoringoperation in the middle of transmitting and receiving URLLC signal maybe skipped. That is, the control channel monitoring operation may behalted in the middle of transmitting and receiving the URLLC signal.

Meanwhile, an indication signal for puncturing or uplink transmissionhalting, which is transmitted from the base station to the UE, may betransmitted per mini-slot or mini-slot group or URLLC TTI indicatedseparately through higher layer signalling. For example, if eMBB andURLLC, which have their respective service requests and/or schedulingunits different from each other, are operated based on a grant of thebase station, the base station may transmit the indication signal forpuncturing or uplink transmission halting to the eMBB UE in the middleof transmitting eMBB uplink to receive URLLC uplink transmission throughtime and frequency resources partially superposed on eMBB uplinktransmission region.

At this time, the indication signal may be transmitted at the time whena grant signal for URLLC uplink transmission is transmitted or from thetime when the grant signal is transmitted to the time before URLLCuplink transmission is performed. The eMBB UE may delay or halt eMBBuplink transmission from a specific time (for example, next mini-slot(group)) after the indicated signal transmitted from the base station isreceived/detected. At this time, the specific time may correspond to amini-slot or mini-slot group after the indication signal isreceived/detected. Meanwhile, the embodiment of the indication signalmay be extended/applied to downlink transmission in addition to uplinktransmission for eMBB/URRLC.

In the next generation system, in respect of eMBB and URLLC having theirrespective service requests and/or scheduling units different from eachother, downlink resources may partially be used as URLLC downlinktransmission while eMBB downlink transmission is being performed. Also,in order that the eMBB UE performs suitable demodulation and decoding,indication signalling for a part of downlink resources used for URLLCdownlink transmission may be transmitted.

Also, when the indication signalling is transmitted per mini-slot ormini-slot group, the indication signalling may include (1) informationas to whether eMBB downlink transmission which is ongoing has beenpunctured by URLLC downlink transmission and punctured resourceinformation. Also, the indication signalling may include (2) informationas to whether eMBB uplink transmission which is ongoing has beendelayed/halted by URLLC uplink transmission, and may include resourceinformation used for URLLC uplink transmission.

Meanwhile, the indication signalling may indicate (1) a resource regionnot information for a UE for demodulating and decoding downlink data.Also, the indication signalling may include (2) information as to whenuplink transmission is delayed or halted or target resource information.The information may briefly be configured in the form of a bitmap of 2bits. MSB (Most Significant Bit) may be information on downlink, and LSB(Least Significant Bit) may be information on uplink. Alternatively, theindication signal may be configured in the form of mapping informationon downlink/uplink multiplexing of eMBB/URLLC into another sequence.

Meanwhile, if grant-free based uplink transmission is considered, it maybe inefficient that the base station end controls a scheme of on-goingtransmission. For example, if URLLC performs grant-free based uplinktransmission and traffic for URLLC occurs intermittently, the basestation end cannot know when eMBB uplink transmission is halted. Tosolve this problem, it may be considered that a resource of a target forthe transmission delay or the transmission halting is previouslyconfigured through higher layer signalling.

<Superposition of eMBB and URLLC>

It may be considered that eMBB and URLLC are simultaneously transmittedfrom the same resource. A power ratio between two uplink channels may beconfigured at a certain level or more, and eMBB signal and URLLC signalmay be subjected to superposition, whereby the base station end maydetect two uplink channels through an interference cancellation scheme.

Basically, the eMBB uplink may be being transmitted, and considering QAMmodulation, it is favourable that a power is maintained in the middle oftransmitting the eMBB uplink channel, whereby the power of URLLC may bechanged suitably. Meanwhile, in accordance with the status or powerconfiguration of the eMBB UE, the transmission power of the URLLC signalmay be configured to be smaller than the transmission power of the eMBBuplink signal, or vice versa. In other words, the transmission power ofthe URLLC signal may be scaled based on the transmission power of theeMBB signal. At this time, it is required that a signal having arelatively great transmission power should first be detected.

At this time, considering a latency aspect, a network may allow onlythat eMBB signal of a relatively low transmission and reception power issuperposed on URLLC uplink signal of a relatively high transmission andreception power. In this case, the URLLC signal should be cancelledfully or at a certain level or more to decode the eMBB signal. To thisend, information on the URLLC signal may be notified to the eMBB UEUE-specifically, cell-commonly, or UE group-specifically.

At this time, the aforementioned method may be limited to downlinktransmission. If the aforementioned method is applied to uplinktransmission, the aforementioned method may be limited to the case thatuplink transmission occurs for the same network. This is because thatthe network should know both of demodulation information and decodinginformation on eMBB and URLLC uplink transmission to performdemodulation and decoding for uplink transmission.

At this time, candidates for information on URLLC signal decoding maypreviously be defined, or may be indicated to the UE by the networkthrough signaling. Furthermore, indication through network signaling maybe performed by a higher layer, or may be performed by selecting aspecific candidate through DCI after candidates are configured by thehigher layer. The DCI may be group common DCI or DCI for scheduling eMBBdata.

Meanwhile, the URLLC signal may have a relatively high power, and thusmay perform decoding regardless of the presence of the eMBB signal. Ifsuperposition of an opposite direction is considered, that is, if URLLCof a relatively low transmission and reception power is superposed oneMBB signal of a high transmission and reception power, descriptionposition of the eMBB signal and the URLLC signal in the above embodimentmay be changed. At this time, if information on the eMBB signal isprovided to URLLC UE, information on a specific code block group may beprovided.

Meanwhile, grant based scheduling may be considered for eMBB uplinkchannel, and both grant based scheduling and grant-free based schedulingmay be considered for URLLC uplink channel. Particularly, superpositionbetween the URLLC signal and the eMBB signal may be configured throughpower control, that is, TPC (Transmission power control) between grantbased uplink channel transmissions.

For example, TPC and/or offset higher layer signaled may be set to asuitable value. However, if TPC value or offset range has a greatcontrol width and a superposition operation is configured by a higherlayer, a range of the TPC value and/or a range of the offset valuehigher layer signaled may be changed.

Meanwhile, a resource to which eMBB and URLLC may be transmitted bybeing subjected to superposition may be configured semi-statically, andURLLC scheduling within the corresponding resource may be performeddynamically based on grant. At this time, the eMBB UE may individuallyapply a transmission power to a resource to which URLLC may betransmitted and a resource to which URLLC is not transmitted, and TPCinformation applied to the resource to which URLLC may be transmittedmay be received through higher layer signaling.

At this time, it may be considered that different resources havingdifferent power configurations are configured for single uplinktransmission. For example, a relatively low uplink transmission powermay be configured for a resource considering superposition or aguaranteed resource for URLLC transmission, as compared with the otherresources.

Also, phase continuity may not be ensured during power change.Therefore, a separate pilot or reference signal may be added even forthe guaranteed resource.

Next, a detailed embodiment of a UE operation method in the guaranteedresource will be described. Particularly, a method for transmitting eMBBuplink will be described.

Embodiment 2-1

Transmission may not be performed except eMBB signal or referencesignal, and a specific signal such as UCI. That is, for URLLCtransmission, eMBB uplink transmission may be punctured or rate matchedin a corresponding resource.

Embodiment 2-2

A low eMBB transmission power may be configured except eMBB signal orreference signal, and a specific signal such as UCI. In detail, atransmission power or power density for a guaranteed resource may beconfigured by additional offset in proportion to a transmission power ina non-guaranteed resource, and independent power control may beperformed. In this case, independent power control may mean that higherlayer signaled offset configuration and/or TPC may be controlledindependently.

Embodiment 2-3

Application of OCC (orthogonal cover code) to a frequency and/or timedomain may be considered. For example, OCC of a 2 length or OCC of a 4length may be applied to a specific PRB set (for example, single PRB) ona frequency axis, and multiplexing between eMBB and URLLC, which havetheir respective service requests and/or scheduling units different fromeach other, may be supported based on the OCC.

For example, the eMBB signal and the URLLC signal may repeatedly bemapped for the even numbered subcarrier and the odd numbered subcarrierper PRB and OCC may be configured for each of the subcarriers. Indetail, a coded symbol corresponding to the even numbered subcarrierindex may be multiplied by +1, and a coded symbol corresponding to theodd numbered subcarrier index may be multiplied by −1 or +1 inaccordance with service or UE.

Alternatively, the eMBB signal and the URLLC signal may repeatedly bemapped into first six subcarrier indexes and next six subcarrier indexeswithin each PRB, and OCC may be configured for each of the subcarrierindexes.

In the schemes of the aforementioned embodiments 2-1 to 2-3, a specificscheme may be selected and applied, and the base station may configurethe specific scheme through DCI or higher layer signaling. At this time,the DCI may be DCI for scheduling corresponding uplink transmission.Also, URLLC which becomes a target of multiplexing is not limited togrant based uplink transmission, and may be extensively applied togrant-free based uplink transmission.

Meanwhile, in case of a grant-free based uplink channel, a power controlat the base station end may be restrictive, and in this case,superposition between eMBB data and URLLC data may not be supported. Inthe above case, the eMBB data may be rate matched or punctured for theresource configured for grant-free based URLLC. Also, the resourceconfigured for the URLCC may be comprised of all of candidates for whichgrant-free uplink transmission may be performed, or the eMBB may beindicated by the base station through higher layer signaling or DCI inthe form of a separately guaranteed resource.

On the other hand, if superposition between the eMBB signal and theURLLC signal is supported, a power may be configured at the base stationend on the basis of higher layer signaled offset. In detail, TPC for agrant-free mode may be configured through a separate channel such asgroup common DCI or UE-specific DCI. At this time, a TPC command may notbe for accumulation but be power configuration for a first grant-freetransmission resource after the TPC command is transmitted. Otherwise, apower for various grant-free transmission resources may be configuredthrough a TPC command, and a grant-free transmission resource, whichwill be applied, may be configured through a higher layer, or may beindicated dynamically through DCI. Meanwhile, a value transmittedthrough TPC may be an offset value or a power control parameter such asPO or alpha, and the corresponding parameter may be configured based onpathloss measured by the UE to calculate a power.

Meanwhile, if URLLC and eMBB are subjected to superposition, the eMBB UEmay perform rate matching by emptying a corresponding resource elementwithout transmitting a signal from a resource element to which DMRS ofURLLC may be transmitted. Otherwise, a sequence (for example, referencesignal) orthogonal to URLLC DMRS may be transmitted from a resourceelement to which DMRS of URLLC is transmitted. Channel estimation ofURLLC may stably be performed even in the case that superposition occursthrough the aforementioned methods. If URLLC is first decoded and theneMBB is decoded, URLLC signal may be transmitted from the resourceelement to which DMRS of eMBB is transmitted. This is because thatdecoding of the eMBB signal may be attempted after the URLLC signal isremoved if URLLC is successfully decoded, and reliability of URLLC isgenerally higher than that of eMBB.

Meanwhile, the URLLC UE may be allowed to detect uplink grant of theeMBB UE or a UE which uses a grant-free mode may be allowed to detectuplink grant for the URLLC signal. At this time, in order that the URLLCUE is allowed to detect uplink grant of the eMBB the UE which uses agrant-free mode is allowed to detect uplink grant for the URLLC signal,masking is performed with group RNTI instead of RNTI per UE, whereby UEID may be transmitted through payload. At this time, UE ID may be ID ofa UE which performs grant based uplink transmission or UD of the eMBBUE. If DCI of two stages is used, the first DCI may be masked with groupRNTI to first indicate information on resource allocation, and thesecond DCI may be masked with RNTI per UE to indicate information onresource allocation.

If the aforementioned DCI is received by the UE of the grant-free mode,the UE may perform an operation for enhancing reliability by sensingthat grant-free uplink transmission may collide with grant basedtransmission during grant-free uplink transmission and droppingtransmission, or greatly increasing power offset of grant-free uplinktransmission.

Also, to avoid collision with a grant based UE, a frequency domain of agrant-free transmission resource may be changed dynamically. Forexample, a system bandwidth is divided into M subbands and a subband towhich a grant-free resource may be allocated may be notifieddynamically.

Meanwhile, collision may occur even between grant-free uplinktransmissions. In this case, if an uplink channel is mapped for a fullresource for grant-free uplink transmission or a resource reserved forgrant-free uplink transmission, OCC may be applied. In detail,grant-free uplink transmission transmitted from a resource forgrant-free uplink transmission, that is, a resource guaranteed forgrant-free uplink transmission may repeatedly be mapped into acorresponding coded symbol or OCC may be applied for the coded symbol.

For example, supposing that OCC o0, o1, o2, . . . , oM−1 are used forsubcarrier indexes f0, f1, . . . , fN−1, coded symbols c0, c1, c2, . . .may be mapped in a guaranteed resource in a way such as c0*o0, c0*o1, .. . , c0*oM−1, c . . . . The above OCC application method is onlyexemplary, and an actual mapping order may be interleaved. At this time,OCC sequences may be selected differently for different UEs, andgrant-free uplink transmission for UEs which use different OCCs may bedivided and identified at the base station end. Generally, the trafficamount of URLLC may be relatively smaller than other data traffic, andthus resource increase according to OCC application may beinsignificant.

<URLLC Repetition>

In the next generation system, URLLC may perform repeated transmissionas a part of a method for achieving requirements of reliabilityacquisition. Considering that URLLC service is changed at a long timeinterval, URLLC transmission repetition times for a single channel maybe configured through higher layer signaling. Alternatively, as theamount of URLLC traffic is changed, to reflect this, DCI mayadditionally indicate information on URLLC repetition transmission. Thatis, URLLC repetition transmission based on configuration through ahigher layer or DCI may be configured by the base station by properlyconsidering an influence of eMBB and URLCC.

As another method, URLLC signal may be repeated until ACK for a specificchannel is received. For example, an uplink channel may be repeatedlytransmitted until a corresponding ACK is received. In detail, after ACKis received, considering the time when ACK is detected, repetitiontransmission for an uplink channel may be halted after a certain timefrom the time when ACK is received. In addition, repetition transmissionmay be halted from next symbol, next mini-slot or next URLLC TTI fromthe time when ACK is received. Alternatively, the time when actualrepetition transmission is halted may be configured depending on UEcapability/higher layer signaled offset/L1 indication such as DCI or ACKchannel.

However, if the time when ACK is received is delayed, the repetitiontransmission times may be increased excessively, and throughputdegradation of eMBB may be caused unnecessarily. In case of grant-freebased transmission, collision between uplink transmissions may occurmore frequently. To reduce such collision, it may be considered thatrepetition transmission is halted even in the case that NACK isreceived, and retransmission may newly be performed in accordance withnew scheduling information in the corresponding case. At this time, theretransmission may be performed repeatedly in accordance with higherlayer signaling and/or indication of DCI.

On the other hand, maximum transmission repetition times may beconfigured. Repetition transmission may be performed so as not to exceedthe corresponding maximum transmission repetition times even before ACKor NACK is actually received. At this time, if there is a blank resourceor invalid resource within the corresponding interval, URLLCtransmission may be delayed, or actual transmission may not be performedalthough included in the repetition transmission times.

Meanwhile, if a slot type is indicated dynamically through a commonsignal, a grant-free transmission resource may dynamically be valid ornot. For example, if a slot comprised of a contention-free resource isconfigured as a downlink centric slot or a downlink dedicated slot,uplink repetition transmission may be delayed, or actual transmissionmay not be performed although included in the repetition transmissiontimes. Additionally, if grant-free transmission resources are configuredcontinuously, it may be assumed that repetition transmission occurscontinuously.

Meanwhile, embodiments in which the network may identify initialtransmission and retransmission from each other are as follows.

(1) Grant-free transmission resources for initial transmission andretransmission, that is, grant-free frequency/time/code resources may beconfigured differently. In detail, grant-free transmission resources maybe configured differently even in accordance with a retransmissionorder. For example, in case of the Nth retransmission, resources may beconfigured differently from the other retransmission, or grant-freetransmission resources may be configured differently per retransmissionorder or group based on the order.

The above resources may be configured separately by a higher layer, ormay be changed depending on a specific pattern within a resourceconfigured for URLLC uplink. Meanwhile, if collision between URLLCtransmission and eMBB transmission occurs in initial transmission,collision should not occur during retransmission. To this end, a hoppingpattern may be configured differently through UE-specific parameter orUE-RNTI.

(2) DMRS patterns used for initial transmission and retransmission maybe configured differently from each other. That is, different DMRSpatterns may be rate matched, whereby initial transmission andretransmission may be identified from each other during DMRS detection.In detail, the DMRS patterns may be configured differently even inaccordance with a retransmission order. For example, in case of the Nthretransmission, resources may be configured differently from the otherretransmission, or the DMRS patterns may be configured differently perretransmission order or group based on the order.

(3) UCI including Redundancy Value (RV), New Data Indicator (NDI), etc.is transmitted together with data at a grant-free transmission resource.In detail, a resource for UCI of a grant-free uplink resource may beconfigured separately through higher layer signaling, or may betransmitted from a resource previously fixed within the grant-freetransmission resource. At this time, the previously fixed resource maybe a resource having the lowest frequency index or the highest frequencyindex, or may be a specific frequency index set.

(4) RVs used for initial transmission and retransmission may beconfigured differently from each other. The base station may determineinitial transmission through a decoding metric through blind detectionfor RV.

The followings may be considered for power configuration for URLLCuplink transmission.

(1) Power ramping may be performed within a repetition transmissioninterval. In this case, the number of repetition transmission times maybe reduced. For example, a specific basic unit for power ramping in arepetition transmission interval may be configured, and thisconfiguration may be indicated through a higher layer.

(2) Power may be maintained uniformly within the repetition transmissioninterval. In this case, unnecessary power consumption may be avoided.

(3) Power ramping may be performed during grant-free basedretransmission. Since it may be difficult to perform dynamic powercontrol through DCI, the power may be increased based on retransmission.

(4) The power within the repetition transmission interval may be changedin accordance with a specific pattern. The pattern may previously bedesignated through UE-ID, or the base station may indicate the patternthrough higher layer signaling and/or DCI.

For example, if a power difference is different in accordance with arepetition transmission order between grant-free uplink transmissionscolliding in the same resource set, it may be favourable forsuperposition.

In detail, it is assumed that a power value of a first uplinktransmission is great in a specific resource and a power value of asecond uplink transmission is great in another specific resource. Atthis time, the base station may perform detection for the first uplinktransmission having a relatively strong received power in a specificresource, and then may attempt detection of the second uplinktransmission through SIC, etc.

Meanwhile, in the other resource, superposition between the seconduplink transmission and the first uplink transmission may beseparation-detected efficiently using the detection information. Also,in the same manner as the grant-free based uplink transmission, theaforementioned method may be useful for the status that a power cannotbe changed variably.

In detail, power configuration within the repetition transmissioninterval may include 0. This may mean TDM and/or FDM between DMRS and/orbetween data. At this time, the DMRS may be subjected to CDM betweendifferent UEs, and the data may only be subjected to TDM or FDM. In thiscase, the expression that the DMRS are subjected to CDM betweendifferent UEs means that a power for the DMRS is not 0.

<Signaling Scheme for Indicating Impacted Resource>

In the next generation system, data traffics having their respectiveservice requirements and/or scheduling units different from each other,for example, data traffics of eMBB and URLLC may be scheduled on thesame resource, and a specific data traffic may be impacted by anotherdata traffic in the corresponding case. For example, a part of datatraffic of the eMBB may be corrupted by URLLC data traffic, or a part ofa resource into which data traffic of the eMBB is mapped may bepunctured. Also, transmission of eMBB data may be delayed or halted. Theresource impacted as above may be referred to as an impacted resource,and the base station may transmit an indication signal for indicatingthe impacted resource to the UE. By using the indication signal, the UEmay delete a corrupted coded symbol from a buffer or perform a task fornot using the corrupted coded symbol for decoding with respect todownlink reception, and may blank a specific resource or delay or halttransmission with respect to uplink transmission.

The indication signal may include both information on an impactedresource of a downlink and information on an impacted resource of anuplink. Alternatively, an indication signal of the information on animpacted resource of a downlink and an indication signal of theinformation on an impacted resource of an uplink may be transmittedseparately.

Contents and the amount of contents may be varied depending on aposition to which the indication signal is transmitted. For example, ifthe indication signal may be transmitted per mini-slot or mini-slotgroup or in a scheduling unit for URLLC, contents may include small bitsof 1 bit or 2 bits, which may indicate whether the impacted resourceexists. In this case, the indication signal may indicate a state througha sequence, like PCFICH or SRS, or may indicate the state as amodulation symbol, like PHICH or PUCCH.

At this time, a physical channel to which the indication signal istransmitted may follow only a transport format for PCFICH, PHICH, etc.,and the indication signal is transmitted from the position to which thecorresponding physical channel is actually transmitted, wherein theindication signal may be allocated to a position of a resource, to whicha specific PHICH group is transmitted, and/or PHICH sequence or OCCindex. Although the base station transmits the indication signal, atransport format of the indication signal may be based on SRS transportor PUCCH transport format.

The indication signal may include more detailed information on animpacted resource, such as time/frequency resource information or codeblock/code block group information in which the impacted resource isincluded, or may perform encoding and/or CRC attachment for theinformation on the impacted resource per a plurality of mini-slots/minislot groups, scheduling unit for URLLC, and code block/code block group.In this case, as a physical channel that may transmit the indicationsignal, a PDCCH or a PUCCH may be used. At this time, the physicalchannel that may transmit the indication signal means a type of achannel to which the indication signal is transmitted, and the basestation may transmit the indication signal at a specific time on thebasis of uplink transmission in addition to a downlink signal. That is,if the base station transmits the indication signal to the UE, thiscorresponds to downlink transmission but means that the indicationsignal may be transmitted based on a transport format of PUCCH.

A detailed embodiment of a method for expressing an impacted resourcefor a plurality of mini-slots/mini slot groups will be described.

Embodiment 3-1

The presence of an impacted resource may be expressed in the form of abitmap per a plurality of mini-slots/mini slot groups, scheduling unitfor URLLC, and code block/code block group.

If the presence of an impacted resource is expressed in the form of abitmap with respect to all resources, and if the amount of traffic forURLLC is great, signaling overhead may be increased unnecessarily.Therefore, when an impacted resource for uplink is expressed togetherwith an impacted resource for a downlink, information on impactedresources of downlink/uplink may be expressed in the form of bitmap perthe aforementioned unit. In other words, the presence of an impactedresource for each of a plurality of mini-slots/mini slot groups,scheduling unit for URLLC, or code block/code block group may beexpressed in the form of a bitmap.

Embodiment 3-2

The presence of an impacted resource for a plurality of mini-slots/minislot group, scheduling unit for URLLC, or code block/code block groupmay be expressed in the form of a specific pattern. If the amount ofURLLC traffic is small, a portion impacted by URLLC transmission duringeMBB transmission of a great scheduling unit may be limited to severalmini-slots/mini slot groups. Therefore, the information on an impactedresource may be expressed as being limited to a specific pattern set.For example, if the number of mini-slots/mini-slot groups is 7 withineMBB TTI, examples of possible patterns include [1 0 0 0 0 0 0], [0 1 00 0 0 0], . . . , [0 0 0 0 0 0 1], . . . , [1 1 1 1 1 1 1].

Another method may indicate a start point where an impacted resource isgenerated and an end point. If repetition transmission is introduced forURLLC of a small scheduling unit, the above indication values mayexpress a start point of the impacted resource, and the actual impactedresource may be expressed as a corresponding start point and repetitionnumber.

In detail, considering network flexibility, the pattern, a scheme of apattern which is indicated, number of cases for a pattern combinationmay be configured by a higher layer. If an impacted resource of anuplink is expressed together with an impacted resource for a downlink, avalue expressed in each pattern may be replaced with the information onan impacted resource in a downlink and/or an uplink.

At this time, whether a time domain resource is expressed in the form ofbitmap or pattern may be indicated by the base station through higherlayer signaling, DCI and/or group common PDCCH.

In the aforementioned embodiment, if a pre-empted resource is indicatedby combination of specific patterns, retransmission of URLLC signalcorresponding to the pre-empted resource may be scheduled together withthe pre-empted resource. In this case, the pre-empted resource byretransmission may be indicated.

For example, when a pre-empted resource is indicated, a pre-emptedresource corresponding to initial transmission may be indicated, and apre-empted resource corresponding to retransmission after a specifictime from the time when corresponding initial transmission occurs mayadditionally be indicated. At this time, the specific time correspondingto retransmission may be a fixed value or a value configuredsemi-statically.

The resource corresponding to retransmission may always be indicated inthe form of a resource set when a pre-empted resource for initialtransmission occurs, or when the pre-empted resource is indicated, as a1-bit flag exists in an indicator for the pre-empted resource, whetherto indicate only a pre-empted resource for initial transmission orwhether to indicate all of the pre-empted resources for initialtransmission and retransmission may be configured. Otherwise, a patternfor retransmission may additionally be indicated.

In this case, when a 1-bit flag is used, if the indicator for thepre-empted resource includes information on a slot of the pre-emptedresource, a field indicating information on a slot and a fieldindicating the pre-empted resource may be configured in combination. Forexample, when HARQ RTT includes 4 symbol groups, the pattern may beenlarged as follows.

[1 0 0 0 0 0 0], [0 1 0 0 0 0 0], . . . , [0 0 0 0 0 0 1], . . . , [1 11 1 1 1 1], [1 0 0 0 1 0 0], [0 1 0 0 0 1 0], [0 0 10 0 0 1], [0 0 0 1 00 0|1], . . . , [0 0 0 0 0 0 1|0 0 0 1], [1 1 1 1 1 1 1|1 1 1 1].

That is, if the pre-empted resource corresponding to retransmission isindicated, the information on a pre-empted resource may be enlarged toinformation on a plurality of slots.

As another embodiment, as the information on a pre-empted resource, astarting slot index at which a pre-empted resource within a specificinterval first occurs may be indicated, and a plurality of slotintervals from the corresponding slot or a symbol group where thepre-empted resource within the specific interval occurs may beindicated. In detail, the specific interval may be two slots, and thusthe information on the pre-empted resource may indicate the pre-emptedresource through a bitmap or pattern indication for symbol groups withina plurality of slots and a slot index. The plurality of slot intervalsand/or the specific interval may be indicated by the base stationthrough higher layer signaling and/or DCI. Otherwise, the plurality ofslot intervals and/or the specific interval may previously be defined.

As another method, as the information on the pre-empted resource, astarting symbol index at which the pre-empted resource within thespecific interval first occurs may be indicated, and the pre-emptedresource which may occur within the specific interval from the symbolgroup index corresponding to the starting symbol index may be indicated.

In the aforementioned embodiment, initial transmission is onlyexemplary, and a transmission period of an indicator for the pre-emptedresource may be configured by a plurality of slots, and positionindication for initial transmission of the aforementioned embodiment maybe replaced with a position for the pre-empted resource first generatedwithin the corresponding slot.

That is, the embodiment may extensively be applied even in case of thepre-empted resource for retransmission in such a manner that theindicator for the pre-empted resource for retransmission may beindicated by a method for indicating the pre-empted resource for initialtransmission, and then the pre-empted resource for retransmission may beindicated by the method for indicating the pre-empted resource forretransmission in the aforementioned embodiment.

Meanwhile, when the pre-empted resource is indicated, the pre-emptedresource may be indicated once over a plurality of slots. This may beuseful when the indicator for the pre-empted resource is transmitted ata specific period. Simply, the pre-empted resource may be indicated inthe form of bitmap with respect to a specific area. At this time, thespecific area indicated in the form of bitmap may be designatedseparately by the base station or may be configured equally to thetransmission period of the indicator for the pre-empted resource. Thiswill be described later in detail. Meanwhile, the specific areaindicated in the form of bitmap may be defined in the form ofcombination of a time domain corresponding to the specific interval anda specific frequency domain.

According to the aforementioned embodiment, when the specific area isconfigured greatly at a certain area or more, if the grate specific areais indicated in the form of bitmap, excessive signaling overhead of theindicator may be generated.

To solve this, it may be considered that the specific area is indicatedin the form of pattern. URLLC traffic corresponding to the pre-emptedresource may not occur frequently, and thus a maximum number of times atwhich the pre-empted resource is generated may be restrictive within thespecific interval. Therefore, the pattern for the specific area mayinclude a pattern for a case that the pre-empted resource is generatedonly once within the specific area based on a basic unit of thepre-empted resource, which is designated based on indicated time-domaingranularity. Similarly, the pattern for the specific area may include apattern for a case that the pre-empted resource is generated within thespecific area as much as N times. At this time, a value of N may be 1 to3, or may be a value previously determined like a size of the specificarea or may be indicated by the base station through higher layersignaling and/or DCI, or may be configured in accordance with a size ofgroup common DCI.

In detail, when a number of a time unit at which the pre-empted resourcemay be generated within the specific area is M, a size of a bit fieldfor pre-emption indication may be set to Ceil(log 2(COMBIN(M, 1)+COMBIN(M, 2)+ . . . +COMBIN (M, N))), wherein COMBIN (p, q) may be defined asp!/(q!*(p−q)!).

Meanwhile, the aforementioned description may be summarized as follows.

(1) Option 1: The pre-empted resource is indicated within a referencetime region in a bitmap.

(2) Option 2: The pre-empted resource is indicated within a referencetime region in the form of pattern. At this time, the pattern mayindicate the pre-empted resource generated within a reference timeregion N times.

(3) Option 3: A procedure of two steps for indicating the pre-emptedresource may be supported. The first step indicates one or more slots atwhich the pre-empted resource is first generated within a reference timeregion. The second step indicates a symbol group corresponding to thepre-empted resource within indicates slots.

In this case, the option 3 may be categorized into option 3-1 and option3-2. According to the option 3-1, in the first step, one of slots withinthe reference time region is selected as a slot at which the pre-emptedresource is first generated. In the second step, a symbol group, whichincludes pre-empted resources existing within M slot from the indicatedslot, is indicated in the form of bitmap. According to the option 3-2,the first step is the same as the option 3-1, and in the second step,pre-empted resources existing within M slot from the indicated slot,which are generated N times, are indicated in the form of pattern.

(4) Option 4: A procedure of two steps for indicating pre-emptedresource may be supported.

In the first step, slots which include the pre-empted resource withinthe reference time region may be indicated using a bitmap. In the secondstep, a symbol group, which includes pre-empted resources within oneslot, is indicated using a bitmap, and this information is commonlyapplied to the slots indicated in the first step.

FIG. 8 illustrates an embodiment of a bit field size according to eachof the aforementioned options and the reference time region.

As described above, impacted resources for a time domain such asmini-slot/mini-slot group or symbol/symbol group may be indicatedseparately or in combination to indicate impacted resources in afrequency domain. In the next generation system, a bitmap or patterntype may be indicated in accordance with a resource block group (RBG)size configured or indicated by a method for expressing frequency domainresources, or a bandwidth part (BWP) or system bandwidth is divided inaccordance with a specific value N which is configured or indicated, oran impacted resource may be indicated in the form of bitmap or patternin accordance with the divided part.

The impacted resource may be indicated based on a resource for a PDSCHused for URLLC transmission, and may additionally include a PDCCHresource for scheduling the PDSCH, and the impacted resource may beindicated based on the PDCCH resource. Also, when a plurality ofmini-slots or symbols/symbol groups indicate the impacted resource, theimpacted resource indicated in the frequency domain may include a unionof impacted resources in a plurality of mini-slots or symbols/symbolgroups.

For example, when impacted resources for N PRB, which are continuous ornot in the frequency domain, may be indicated, and impacted resourcesfor M symbols, which are continuous or not in the time domain areindicated, the final impacted resources may be comprised of N PRBindicated per M symbol which is indicated. That is, the impactedresources may be comprised of N*M resource elements. However, thismethod may require configuration for unnecessarily many impactedresources, and may cause decoding throughput degradation of a PDSCH,which includes impacted resources, and/or increase of resources requiredduring retransmission.

Meanwhile, to solve this problem, frequency domain resources mayindependently be configured per mini-slot/mini-slot group orsymbol/symbol group. In detail, an impacted resource indication value inthe frequency domain may be indicated per single or a plurality ofmini-slots/mini-slot groups or symbols/symbol groups. In addition, afrequency domain impacted resource indication value for a symbol/symbolgroup prior to a specific time within a slot and a frequency domainimpacted resource indication value for the other symbol/symbol group mayexist separately.

Meanwhile, the aforementioned method may be limited to a case that theselected symbol/symbol group is a specific threshold value or more.Particularly, the specific threshold value may be limited to a case thatall symbol groups are selected. Otherwise, in the aforementioned method,an indication value of a frequency domain impacted resource mayseparately be configured for a symbol/symbol group from a specificstarting symbol to a specific order. In detail, when indication for thepre-empted resource indicates occurrence of the pre-empted resource of Mtimes on a time axis, indication of the frequency domain resources maybe M times. At this time, each frequency resource indication maycorrespond to occurrence of each pre-empted resource.

Furthermore, indication of the pre-empted resource may basically expressoccurrence of one or two pre-empted resources, and each pre-emptedresource may be indicated by two frequency resource indication fields.For example, if indication of the pre-empted resources indicates allsymbol groups, indication of two frequency resources may indicatefrequency resources corresponding to a half of a front part and a halfof a rear part of a reference time resource. Alternatively, twofrequency resource indication fields may be incorporated into one andthen may be used as single frequency resource indication. Theaforementioned example is advantageous in that it may clarifyfrequency-domain granularity. Similarly, if indication of the pre-emptedresource indicates the pre-empted resource generated once, two frequencyresource indication fields may be incorporated into one and then may beused as single frequency resource indication. This method isadvantageous in that flushed bits may be reduced using a limited payloadsize when the pre-empted resource is indicated.

FIG. 9 illustrates an embodiment for indicating a pre-empted resource,as described above, wherein FIG. 9(a) illustrates that time/frequencybitmap is used, and FIG. 9b illustrates that a pattern type indicationis performed. That is, referring to FIG. 9, as shown in FIG. 9(a), if abitmap is used, since the presence of pre-empted resources of all oftime and frequency domains should be expressed in restricted bits,granularity is reduced, whereby unnecessarily flushed bits may begenerated remarkably. However, as shown in FIG. 9(b), if a pattern typeis used, since one pattern may be used N times, granularity may beincreased, whereby unnecessarily flushed bits may be reduced.

However, if the pattern type is used as shown in FIG. 9(b), since itindicates whether the resource is pre-empted for a limited specificpart, its exactness in expression may be more lowered than the bitmap.Therefore, to enhance exactness as to whether all of partitions arepre-empted, it may be preferable to use the bitmap as shown in FIG.9(a).

Also, if the pre-empted resources are expressed in the form of bitmap,since it indicates whether each partition is pre-empted, it may bepreferable to use a bitmap when pre-emption of each resource isdynamically changed.

In the next generation system, mini-slot/mini-slot group orsymbol/symbol group may be indicated by the base station through RRCsignaling and/or DCI. Particularly, the base station may indicatecombination of time-domain granularity and frequency-domain granularity.However, in this case, as a size of a reference frequency domain whichbecomes an indication target of the pre-empted resource is changed,combination of another time and frequency granularity may be required.

For example, granularity of a specific direction may be indicated by thebase station and granularity of another direction may be calculatedbased on a payload size for pre-empted resource indication. At thistime, granularity of a specific direction may be time-domaingranularity, and granularity of another direction may befrequency-domain granularity. In detail, if a payload size of pre-emptedresource indication is P, time-domain granularity is subjected togranularity of K symbols, a size of a reference time region is T symbolsand a size of a reference frequency domain is F PRBs, frequency-domaingranularity may be determined in accordance with └F/└P/┌T/K┐┘┘ and/or┌F/└P/┌T/K┐┘┐.

However, this granularity method may generate unnecessary frequencygranularity, and in this case, efficiency of pre-empted resourceindication may be lowered. To mitigate efficiency mitigation, thefrequency-domain granularity may mean that the closest value in apreviously configured set may be selected from the calculated equation.

As another embodiment, the base station may indicate a combination ofthe number of time domain partitions and the number of frequency domainpartitions in the reference resource instead of time and frequencygranularity. Otherwise, the base station may configure a ratio of timeand frequency granularity to a reference resource. For example, the basestation may indicate granularity for the time domain, and may calculatefrequency granularity in accordance with the ratio which is configured.

In respect of the number of time domain partitions and/or the number offrequency domain partitions in the reference resource, a detailedembodiment for a method for configuring actually pre-empted resourceindication information will now be described. A size of the referencetime region for the pre-empted resource may not be a multiple of thenumber of time domain partitions. In this case, when pre-empted resourceindication information is configured, how to configure time-domaingranularity should be determined. Therefore, a method for determiningtime-domain granularity configuration will be described hereinafter. Forconvenience of description, it is assumed that a size of a referencetime region is T symbols and the number of time domain partitions is M.

Embodiment 4-1

If the reference time region is transmitted over a plurality of slots,indication for the pre-empted resource may be performed over a pluralityof slots. For example, a time domain size of each partition may becomprised of └T/M┘ or ┌T/M┐. That is, a size difference betweenpartitions may be maximum 1 symbol.

In detail, the number of partitions having a size of └T/M┘ may be└M┌T/M┐−T┘, and the number of partitions having a size of ┌T/M┐ may beM−└M┌T/M┐−T┘. If the number of the aforementioned partitions isexpressed in another method, the number of partitions having a size of┌T/M┐ may be T−M└T/M┘, and the number of partitions having a size of└T/M┘ may be

$M - {( {T - {M\lfloor \frac{T}{M} \rfloor}} ).}$

At this time, time-domain granularity or a time domain size ofpartitions may be limited to a specific value (K′ candidate) such as 2,4 and 7 symbols. In other words, the smallest K which satisfies M*K>=Tmay be determined, and the greatest K′ which satisfies K′<K may beselected from 2, 4 and 7 symbols. For example, if K is determined as 7,K′ may be 4. ΔK may be defined as K−K′, and in the corresponding case,the number of partitions having a size of K′ may be └(M·K−T)/ΔK┘, andthe number of partitions having a size of K may be M−└(M·K−T)/ΔK┘.

If the base station indicates a ratio between the reference time regionand time-domain granularity, a value of the corresponding ratio may beindicated in the form of a multiple of 1/M, and the method described inthe embodiment 4-1 may extensively be applied.

Embodiment 4-2

Indication for a pre-empted resource may be performed based on one sloteven in the case that the reference time region is transmitted over aplurality of slots. That is, the pre-empted resource indicated by anindicator may be configured so as not to exceed one slot boundary.

For example, when the number of slots constituting the reference timeregion is P, the number M of partitions may be divided per slot. Indetail, the number of partitions per slot may be ┌M/P┐ or └M/P┘, and thenumber of respective slots may be configured such that the number ofslots having partitions as much as └M/P┘ may be └P┌M/P┐−M┘, and thenumber of slots having partitions as much as ┌M/P┐ may be P−└P┌M/P┐−M┘.At this time, the size of each partition may be calculated based on thenumber of symbols within each slot and the number of partitions withineach slot in accordance with the embodiment 4-1.

The above methods may have suitable options different from one anotherin accordance with a type of data transmission assuming actualpre-emption. Also, the above method may be applied extensively even incase of a ratio of partitions in addition to the number of partitions.

Meanwhile, the size of the reference frequency region for pre-emptionmay not be a multiple of the number of frequency domain partitions. Inthis case, when pre-empted resource indication information isconfigured, how to configure frequency-domain granularity should bedetermined. Therefore, a method for determining frequency-domaingranularity configuration will be described hereinafter. For convenienceof description, it is assumed that a size of a reference frequencyregion is F PRBs or F RBGs and the number of frequency domain partitionsis N.

Embodiment 5-1

A frequency domain size of each partition may be comprised of ┌F/N┐ or└F/N┘. That is, a size difference between partitions may be maximum 1PRB or 1 RBG. In detail, the number of partitions having a size of └F/N┘may be └N┌F/N┐−F┘, and the number of partitions having a size of ┌F/N┐may be N−└N┌F/N┘. If the number of the aforementioned partitions isexpressed in another method, the number of partitions having a size of┌F/N┐ may be F−N└F/N┘, and the number of partitions having a size of└F/N┘ may be

$N - {( {F - {N\lfloor \frac{F}{N} \rfloor}} ).}$

At this time, frequency-domain granularity or a frequency domain size ofpartitions may be limited to a specific value. At this time, thespecific value may be set to one of RBG size corresponding to the powerof 2 such as 1, 2, 4 and 8. In this case, the smallest K which satisfiesN*K>=F is selected, and the greatest K′ which satisfies K′<K isselected. For example, if K is 8, K′ may be 4. ΔK may be defined asK−K′, and in the corresponding case, the number of partitions having asize of K′ may be └(N·K·F)/ΔK┘, and the number of partitions having asize of K may be N−└(N·K−F)/ΔK┘.

If the base station indicates a ratio between the reference frequencyregion and frequency-domain granularity, a value of the correspondingratio may be indicated in the form of a multiple of 1/N, and the methoddescribed in the embodiment 3-1 may extensively be applied.

Embodiment 5-2

A frequency domain size of each partition except one of partitionssubjected to granularity includes ┌F/N┐ or └F/N┘, and a size of theother partitions includes F−(N−1)·└F/N┘+ or F−(N−1)·┌F/N┐.

If the base station indicates a ratio between the reference frequencyregion and frequency-domain granularity, it may be assumed that a valueof the corresponding ratio is indicated in the form of a multiple of1/N, and the method described in the embodiment 3-2 may extensively beapplied.

Also, the above method may be applied extensively to the aforementionedembodiments 4-1 and 4-2 even in case of the ratio in addition to thenumber of partitions.

Meanwhile, when an impacted resource is indicated, the impacted resourcemay be indicated by combination of time and domain resources. Forexample, candidates of an impacted resource indication value may beconfigured previously or through higher layer signaling by combinationof time and frequency resources, and one or a plurality of candidates ofthe configured candidates may be indicated through a signal forindicating a pre-empted resource.

The indication signal may be information required for efficientdistribution and use of resources and demodulation and decoding intransmission and reception of data traffics of different services havingtheir respective service requirements and/or scheduling units differentfrom each other. Therefore, if the indication signal is impacted byanother signal, or if a UE is failed in corresponding signal detection,degradation may be generated even in view of entire throughput.Therefore, it may be considered that an indication signal, whichincludes the same or superposed information, is repeatedly transmittedto increase reliability.

For example, an indication signal transmitted per mini-slot/mini-slotgroup may include information on associated mini-slot/mini-slot group.In detail, if a current mini-slot/mini-slot group is a downlinkmini-slot/mini-slot group, the indication signal may include informationon current mini-slot/mini-slot group. On the other hand, if a currentmini-slot/mini-slot group is an uplink mini-slot/mini-slot group, theindication signal may include information on mini-slot/mini-slot groupafter a specific time and information on an impacted resource beforeand/or after the current time. That is, the indication signaltransmitted per mini-slot/mini-slot group may include an impactedresource for mini-slot/mini-slot group until the current time within thesame slot. On the other hand, the indication signal may be transmittedregardless of the presence of occurrence of the impacted resource afterthe time when the impacted resource is generated.

In another way, an indication signal, which includes brief information,may be transmitted per mini-slot/mini-slot group like the presence ofthe impacted resource, and if the impacted resource exists within aslot, an indication signal, which includes an impacted resource for thecorresponding slot, may additionally be transmitted to the lastmini-slot of the slot. At this time, the indication signal additionallytransmitted may include impacted resource information on a plurality ofmini-slots/mini-slot groups. In this case, demodulation and decoding forthe impacted resource may be performed through another indication signaleven in the case that the UE partially fails to detect the indicationsignal.

Meanwhile, the indication signal may be transmitted in the form of asoft-buffer handling indicator within DCI for scheduling PDSCH or PUSCHtogether with a signal comprised of indication information on apre-empted resource. In detail, a pre-empted resource indicator mayindicate an impacted resource in the form of time and/or frequencyresource, and the soft-buffer handling indicator may express an impactedresource per transport block or code block group, wherein corruptedcoded bits within the soft buffer may be identified in accordance with acorresponding value and the UE may flush the corresponding bits.

Embodiments of a method for specifying corrupted coded bits that may beflushed from the soft buffer based on indication information of theplurality of pre-empted resources will be described.

Embodiment 6-1

Of the pre-empted resource indicator and the soft handling indicator,based on information transmitted later, the corrupted coded bits areconfigured. Since the two indicators are information indicated andtransmitted by the base station, it may be useful to repeatedly transmitthe two indicators multiple times to update information on an impactedresource.

Embodiment 6-2

A specific indicator may always first be used to specify corrupted codedbits. In detail, a soft buffer handling indicator within DCI forscheduling PDSCH or PUSCH may always preferentially used. If the basestation supports the soft buffer handling indicator while transmittingthe pre-empted resource indicator, it may be regarded that the basestation intends to use the soft buffer handling indicator. Therefore, ifthe soft buffer handling indicator is not used, it may correspond tounnecessary configuration.

Embodiment 6-3

Corrupted coded bits may be specified by combination of information ofthe pre-empted resource indicator, information of the soft bufferhandling indicator and/or indicated code block group information. Indetail, corrupted coded bits may be specified based on intersection orunion of coded bits indicated by the two indicators.

Embodiment 6-4

Whether the pre-empted resource indicator is used may be varieddepending on a value of the soft buffer handling indicator. For example,if the soft buffer handling indicator is disabled, corrupted coded bitsare specified based on the information of the pre-empted resourceindicator. This case is useful in that soft-buffer combining orsoft-buffer flushing may be performed differently for coded bits relatedto pre-empted resources and the other coded bits. If the soft bufferhanding indicator is enabled, corrupted coded bits may be specifiedbased on the value of the soft buffer handling indicator, or may bespecified by combination of information of the pre-empted resourceindicator, information of the soft buffer handling indicator and/orindicated code block group information.

Meanwhile, the indication signal may be transmitted by the base stationper UE impacted for specific signal transmission by the pre-emptedresource. In this case, each UE may attempt to detect the indicationsignal through its allocated resource, and may properly perform downlinkreception or uplink transmission based on its information.

On the other hand, the indication signal may be transmitted UEgroup-commonly. In this case, a plurality of UEs may attempt to detectthe indication signal from a UE group-specific resource, and mayproperly perform downlink reception or uplink transmission based oninformation included in the indication signal and schedulinginformation.

The embodiment, which will be described later, relates to a method forconfiguring a resource for transmitting a UE-specific indication signal.

Embodiment 7-1

A resource for the indication signal may be configured in conjunctionwith scheduling information on PDSCH which includes an impactedresource. For example, the resource for the indication signal may be apart of a PDSCH resource which includes an impacted resource and/or aperipheral resource of the PDSCH resource. At this time, the peripheralresource of the PDSCH resource may be PRB or PRB group up and down on afrequency axis. If the indication signal is mapped into a part of thePDSCH resource, the resource into which the indication signal is mappedmay be determined by a predefined rule, or a candidate resource in thePDSCH resource which includes an impacted resource may be selected fromone or more candidate resources configured through higher layersignaling. At this time, the predefined rule may be based on that theindication signal is mapped into a frequency having the lowest and/orhighest index.

Embodiment 7-2

Separately from the PDSCH which includes an impacted resource, the basestation may independently configure a resource region, to which theindication signal is transmitted, through a higher layer or DCI. Thatis, the resource to which the indication signal is transmitted may bedesignated UE-specifically. In this case, CDM may be supported among aplurality of indication signals, whereby the resource may be usedefficiently in accordance with a configuration.

Meanwhile, the resource may partially be superposed on the indicationsignal and the PDSCH. If the indication signal and the PDSCH are for thesame UE, the resource for indication signal transmission may bepunctured or rate matched for the corresponding PDSCH. If a resource foran indication signal of a specific UE is superposed on a PDSCH foranother UE by MU-MIMO, the base station may separately indicate, to thespecific UE, a candidate resource set, which becomes a target ofpuncturing and/or rate matching, through higher layer signaling or DCI,and may perform puncturing and/or rate matching for the correspondingcandidate resource set regardless of the presence of transmission of theindication signal.

Distinctively, the candidate resource set may be a superset of resourcesfor a plurality of UE-specific indication signals. At this time, thePDSCH may be a PDSCH for eMBB having a relatively long scheduling unit,or may be a PDSCH for URLLC having a relatively short scheduling unit.Also, if the PDSCH is URLLC PDSCH, it may be considered that theindication signal is also punctured. In this case, a scheduler mayperform resource allocation to minimize superposition between twosignals.

Particularly, if URLLC data are only transmitted and eMBB data are nottransmitted, the base station may indicate whether rate matching orpuncturing for the indication signal or reserved resource is performedfor the URLLC data, through higher layer signaling or URLLC schedulingDCI.

The indication signal may be UE group common signal. At this time, thecandidate resources for the indication signal may be configured groupcommonly through higher layer signaling. Also, the indication signal maybe transmitted by resource allocation per subband or PRB group. That is,for a cell which supports a wideband operation, a specific UE mayperform signal transmission and reception for some subband only.Therefore, in this case, the indication signal for a plurality offrequency resources may be required to be transmitted. At this time,information transmitted through the indication signal for the pluralityof frequency resources may be information on an impacted resource for asubband or PRB group to which the corresponding signal is transmitted.In this case, the information on an impacted resource may indicateinformation as to whether the impacted resource exists or information ona resource configured as an impacted resource.

Also, to enhance reliability, or to reduce detection attempt of theindication signal, impacted resource information on a plurality ofsubbands or PRB groups may be included in the indication signaltransmitted to each subband and PRB group.

Meanwhile, the indication signal may be superposed on some resource forPDSCH. In this case, puncturing or rate matching may be performedregardless of the presence of transmission of a resource reserved forthe indication signal. Otherwise, the base station may performpuncturing or rate matching for the resource to which the indicationsignal is actually transmitted when transmitting the PDSCH. In thiscase, the UE may recognize whether some resource for the signal receivedin accordance with a detected result of a group common indication signalhas been punctured or rate matched by the indication signal.

At this time, the PDSCH may be a PDSCH for eMBB having a relatively longscheduling unit, or may be a PDSCH for URLLC having a relatively shortscheduling unit. Also, if the PDSCH is URLLC PDSCH, it may be consideredthat the indication signal is also punctured. In this case, a schedulermay perform resource allocation to minimize superposition between twosignals.

Meanwhile, in the next generation system, it is considered that thepre-empted resource indication signal is transmitted through groupcommon DCI. At this time, a transmission period or a monitoring periodor monitoring occasion of the group common DCI may be configured to begreater than a slot. In this case, time and/or frequency region that maybe indicated by one pre-empted resource indication signal may bereferred to as a reference region, and a proper value of the referenceregion may be configured for each domain.

Preferably, the reference time region should be configured to be greaterthan or equal to a monitoring period for the pre-empted resourceindication signal. If the reference time region is smaller than themonitoring period for the pre-empted resource indication signal, aregion that cannot be indicated through the pre-empted resourceindication signal occurs, whereby there may be a limitation in reducingthroughput degradation caused by the pre-empted resource.

Hereinafter, detailed embodiments for configuring the reference timeregion will be described.

Embodiment 8-1

The reference time region may be configured equal to the monitoringperiod for the pre-empted resource indication signal. However, if themonitoring period is configured to be short, scheduling flexibility forpre-empted resource indication signaling may be reduced.

Therefore, as shown in FIG. 10(a), the reference time region isbasically configured in accordance with the monitoring period of thepre-empted resource indication signal, but a lower limit value exists inthe reference time region. Therefore, if the monitoring period of thepre-empted resource indication signal is a specific threshold value ormore, as shown in FIG. 10(b), the reference time region is set to aspecific value. In this case, the specific value may be a fixed value,or may be a maximum value or minimum value of HARQ RTT.

Also, in FIGS. 10(a) and 10(b), P indicates a monitoring period of thepre-empted resource indication signal, and X means a specific thresholdvalue.

Embodiment 8-2

The reference time region may be set to a multiple of K of themonitoring period for the pre-empted resource indication signal. The Kmay be indicated by the base station through higher layer signalingand/or DCI.

Embodiment 8-3

Basically, the pre-empted resource indication signal should betransmitted earlier than retransmission corresponding to downlinktransmission including the pre-empted resource.

Therefore, as shown in FIG. 11(a), the reference time region may beconfigured based on HARQ RTT (Round Trip Time) or downlinkdata-to-HARQ-ACK feedback timing. In this case, HARQ RTT may mean thetime when a timing difference between initial transmission andretransmission corresponding to the initial transmission becomes aminimum value.

Meanwhile, in the next generation system, scheduling timing may bechanged dynamically, and the pre-empted resource indication signal maybe configured group commonly. Therefore, the reference time region maybe set to minimum value/maximum value/default value among the valuesavailable as the HARQ RTT or downlink data-to-HARQ-ACK feedback timing.

Embodiment 8-4

The reference time region is configured based on the monitoring periodfor the pre-empted resource indication signal and HARQ RTT or downlinkdata-to-HARQ-ACK feedback timing.

In detail, the reference time region is configured based on themonitoring period for the pre-empted resource indication signal and themaximum value of the HARQ RTT or downlink data-to-HARQ-ACK feedbacktiming values. In the next generation system, scheduling timing may bechanged dynamically. Therefore, the reference time region may be set tominimum value/maximum value/default value among the values available asthe HARQ RTT or downlink data-to-HARQ-ACK feedback timing.

In case of the reference frequency region, the base station may indicatestart/end/interval through higher layer signaling.

UEs which receive the pre-empted resource indication signal may have adifferent bandwidth part (BWP) configured for each UE. Therefore,indexing for a frequency domain resource may also be different. On theother hand, since the pre-empted resource indication signal istransmitted group commonly, if the pre-empted resource on the frequencyaxis is indicated, indexing for the corresponding pre-empted resource isalso required group commonly. For example, numbering or indexing may beperformed in an ascending order from the lowest frequency region bystarting from the region configured as the reference frequency region.Otherwise, group common indexing within the corresponding carrier may beused as it is.

<Method for Indicating Pre-Empted Resource for Scell>

In the next generation system, pre-empted resource indication for aplurality of cells may be transmitted by joint encoding to single DCI.In this case, a reference resource for each pre-empted resourceindication of each cell may be allocated. A reference resource for aPCell or a serving cell to which corresponding DCI is transmitted may beconfigured as a region from a first symbol of a previous monitoringoccasion to a previous symbol of a first symbol of the currentmonitoring occasion on a time axis. Additionally, a symbol indicated byan uplink may be excluded from the reference resource byUL-DL-configuration-common. It may be assumed that the referenceresource is the same as a downlink bandwidth part (BWP), to whichcorresponding DCI is transmitted, on a frequency axis.

Meanwhile, in indication of SCell or a pre-empted resource, it isrequired to define a reference resource for a serving cell, which istransmitted from another cell.

On the time axis, an absolute time duration configured based on amonitoring period of DCI, that is, a reference resource set to a fixedvalue may be configured equally in all serving cells. That is, ifnumerology is different per serving cell, scaling may be performed basedon different numerologies.

For example, it is assumed that a period is T and numerologyconfiguration is u_ref with respect to DCI including a Pre-emptionIndicator (PI). When numerology configuration for a specific servingcell is u, the reference time region may include 14×2^(u-u_ref)×Tsymbols or ┌14×2^(u-u_ref)×T┐ symbols of a previous period.

In detail, if a subcarrier spacing of a serving cell corresponding to apre-empted resource indication field is smaller than a subcarrierspacing corresponding to an actual pre-empted resource indicationtransmission, the pre-empted resource indication field may be configuredat a subcarrier spacing corresponding to actual pre-empted resourceindication transmission. In this case, it is assumed that actual symbolsuperposed on the indicated symbol is pre-empted.

Meanwhile, it may be considered that uplink symbol is excluded from thereference time region in the same manner as a single cell. However,SCell may not receive UL-DL-configuration-common. Therefore, even thoughuplink symbol is excluded from the reference time region for PCell or aserving cell to which DCI is transmitted including pre-empted resourceindication, based on UL-DL-configuration-common, there may be no symboladditionally excluded from the other serving cells.

UL-DL-configuration-dedicated-SCell indicating downlink symbol, uplinksymbol, and flexible symbol may be configured for each serving cell, andthe reference time region may be updated based on the configuredUL-DL-configuration-dedicated-SCell. Alternatively, when pre-emptedresource indication is configured, symbol information which is excludedmay be configured per cell and a specific symbol may be excluded basedon the corresponding configuration.

On the frequency axis, when it is assumed that an active bandwidth part(BWP) is always the same for all UEs, a restriction may occur inbandwidth part switching in SCell. As a method for solving this, areference BWP or resource block (RB) set may be configured throughpre-emption indication configuration.

A target of the above configuration may be limited to SCell or a cell towhich DCI (PI DCI) having pre-empted resource indicator is nottransmitted. Otherwise, a default BWP or initial BWP of thecorresponding SCell may be configured as a reference frequency regionfor the pre-empted resource indicator (PI). Meanwhile, UEs havingdifferent actual active BWPs may disregard information included in thecorresponding pre-empted resource indicator (PI).

Meanwhile, when the pre-empted resource indication for a plurality ofcells is transmitted through single DCI, time and frequency granularitymay be configured independently per cell. That is, information on thenumber of partitions is not required to be applied to all cells, and maybe configured per cell in pre-empted resource indication configurationor may be configured independently for PCell and SCell. Alternatively,since it may be difficult to configure reference frequency resources forSCell, (M, N) may always be assumed as (14, 1). That is, only pre-emptedresource information on the time domain may be indicated for the SCell.The SCell may mean a cell which receives pre-empted resource indicationfrom another cell.

Referring to FIG. 12, a communication apparatus 1200 includes aprocessor 1210, a memory 1220, an RF module 1230, a display module 1240,and a User Interface (UI) module 1250.

The communication apparatus 1200 is shown as having the configurationillustrated in FIG. 12, for the convenience of description. Some modulesmay be added to or omitted from the communication apparatus 1200. Inaddition, a module of the communication apparatus 1200 may be dividedinto more modules. The processor 1210 is configured to performoperations according to the embodiments of the present disclosuredescribed before with reference to the drawings. Specifically, fordetailed operations of the processor 1210, the descriptions of FIGS. 1to 11 may be referred to.

The memory 1220 is connected to the processor 1210 and stores anOperating System (OS), applications, program codes, data, etc. The RFmodule 1230, which is connected to the processor 1210, upconverts abaseband signal to an RF signal or downconverts an RF signal to abaseband signal. For this purpose, the RF module 1230 performsdigital-to-analog conversion, amplification, filtering, and frequencyupconversion or performs these processes reversely. The display module1240 is connected to the processor 1210 and displays various types ofinformation. The display module 1240 may be configured as, not limitedto, a known component such as a Liquid Crystal Display (LCD), a LightEmitting Diode (LED) display, and an Organic Light Emitting Diode (OLED)display. The UI module 1250 is connected to the processor 1210 and maybe configured with a combination of known user interfaces such as akeypad, a touch screen, etc.

The embodiments of the present invention described above arecombinations of elements and features of the present invention. Theelements or features may be considered selective unless otherwisementioned. Each element or feature may be practiced without beingcombined with other elements or features. Further, an embodiment of thepresent invention may be constructed by combining parts of the elementsand/or features. Operation orders described in embodiments of thepresent invention may be rearranged. Some constructions of any oneembodiment may be included in another embodiment and may be replacedwith corresponding constructions of another embodiment. It is obvious tothose skilled in the art that claims that are not explicitly cited ineach other in the appended claims may be presented in combination as anembodiment of the present invention or included as a new claim by asubsequent amendment after the application is filed.

A specific operation described as performed by a BS may be performed byan upper node of the BS. Namely, it is apparent that, in a networkcomprised of a plurality of network nodes including a BS, variousoperations performed for communication with a UE may be performed by theBS, or network nodes other than the BS. The term ‘BS’ may be replacedwith the term ‘fixed station’, ‘Node B’, ‘evolved Node B (eNode B oreNB)’, ‘Access Point (AP)’, etc.

The embodiments of the present invention may be achieved by variousmeans, for example, hardware, firmware, software, or a combinationthereof. In a hardware configuration, the methods according to exemplaryembodiments of the present invention may be achieved by one or moreApplication Specific Integrated Circuits (ASICs), Digital SignalProcessors (DSPs), Digital Signal Processing Devices (DSPDs),Programmable Logic Devices (PLDs), Field Programmable Gate Arrays(FPGAs), processors, controllers, microcontrollers, microprocessors,etc.

In a firmware or software configuration, an embodiment of the presentinvention may be implemented in the form of a module, a procedure, afunction, etc. Software code may be stored in a memory unit and executedby a processor. The memory unit is located at the interior or exteriorof the processor and may transmit and receive data to and from theprocessor via various known means.

Those skilled in the art will appreciate that the present invention maybe carried out in other specific ways than those set forth hereinwithout departing from the spirit and essential characteristics of thepresent disclosure. The above embodiments are therefore to be construedin all aspects as illustrative and not restrictive. The scope of thedisclosure should be determined by the appended claims and their legalequivalents, not by the above description, and all changes coming withinthe meaning and equivalency range of the appended claims are intended tobe embraced therein.

INDUSTRIAL APPLICABILITY

Although the aforementioned method for indicating pre-empted resourceinformation in a wireless communication system and the apparatustherefor have been described based on the 5th generation NewRAT system,the method and the device may be applied to various mobile communicationsystems.

The invention claimed is:
 1. A method for transmitting a downlink signalby a base station (BS) in a wireless communication system, the methodcomprising: transmitting information for informing whether a downlinksignal is transmitted in each of a plurality of durations included in aspecific time region; and transmitting the downlink signal based on theinformation, wherein a number of the plurality of durations is M,wherein the plurality of durations include i) one or more firstdurations in which each of the first durations has a first size and ii)one or more second durations in which each of the second durations has asecond size, and wherein the first size is defined by Ceil(T/M), and thesecond size is defined by Floor(T/M), where T denotes a number ofsymbols of the specific time region.
 2. The method according to claim 1,wherein the first size and the second size are different.
 3. The methodaccording to claim 1, wherein a number of the one or more firstdurations having the first size is M−Floor(M×Ceil(T/M)−T) and a numberof the one or more second durations having the second size isFloor(M×Ceil(T/M)−T).
 4. The method according to claim 1, wherein theplurality of durations are configured for the specific time region and aspecific frequency region.
 5. The method according to claim 1, whereinthe specific time region includes the plurality of durations and a timeregion for uplink transmission.
 6. The method according to claim 1,wherein the information includes a plurality of bits for informingwhether the downlink signal is transmitted in each of the plurality ofdurations.
 7. A base station (BS) for transmitting a downlink signal ina wireless communication system, the BS comprising: at least onetransceiver; at least one processor; and at least one computer memoryoperably connectable to the at least one processor and storinginstructions that, when executed by the at least one processor, performoperations comprising: transmitting, via the at least one transceiver,information for informing whether a downlink signal is transmitted ineach of a plurality of durations included in a specific time region; andtransmitting, via the at least one transceiver, the downlink signalbased on the information, wherein a number of the plurality of durationsis M, wherein the plurality of durations include i) one or more firstdurations in which each of the first durations has a first size and ii)one or more second durations in which each of the second durations has asecond size, and wherein the first size is defined by Ceil(T/M), thesecond size is defined by Floor(T/M), where T denotes a number ofsymbols of the specific time region.
 8. The BS according to claim 7,wherein the first size and the second size are different.
 9. The BSaccording to claim 7, wherein a number of the one or more firstdurations having the first size is M−Floor(M×Ceil(T/M)−T) and a numberof the one or more second durations having the second size isFloor(M×Ceil(T/M)−T).
 10. The BS according to claim 7, wherein theplurality of durations are configured for the specific time region and aspecific frequency region.
 11. The BS according to claim 7, wherein thespecific time region includes the plurality of durations and a timeregion for uplink transmission.
 12. The BS according to claim 7, whereinthe information includes a plurality of bits for informing whether thedownlink signal is transmitted in each of the plurality of durations.